Diabetes and the HOPE study: implications for macrovascular and microvascular disease

Diabetes is a major risk factor for cardiovascular events. Indeed, people with diabetes are 2-4 times more likely to die from cardiovascular causes than individuals without diabetes. Despite evidence to suggest that the burden of cardiovascular disease may be decreasing in Western populations, this trend has not been repeated in diabetic populations. Diabetes is also the most common cause of new-onset end-stage renal disease, blindness and amputations. The growing incidence of diabetes throughout the world, particularly in developing nations, suggests that diabetes-related cardiovascular disease and other chronic cardiovascular diseases will constitute a serious global threat to health and well-being. The HOPE (Heart Outcomes Prevention Evaluation) study was designed to determine if the angiotensin converting enzyme (ACE) inhibitor, ramipril, prevents cardiovascular events in high risk patients. As people with diabetes have a high risk of such events, this group was specified for inclusion and analysis in the HOPE study. The HOPE study was designed to include up to 4,000 people with diabetes and was designed with high power to detect an 18% risk reduction in the diabetic sub group alone. A total of 3,577 individuals with diabetes were randomised to receive either 10 mg of ramipril or placebo. After a period of 4.5 years of follow-up, the group of patients receiving ramipril had a statistically and clinically significant risk reduction of 25% in the primary outcome of myocardial infarction (MI), stroke or cardiovascular (CV) death. This comprises a 37% risk reduction in CV death, a 22% risk reduction in MI, a 33% reduction in stroke and a 24% reduction in all-cause mortality. The MICRO-HOPE (Microalbuminuria, Cardiovascular, and Renal Outcomes) sub study assessed the effect of ramipril on diabetic nephropathy. This was detected by a centrally measured urine albumin:creatinine ratio and confirmed by timed urine collection. Ramipril significantly reduced the risk of overt nephropathy by 22% (P = 0.045), and overt nephropathy, laser therapy or dialysis by 15% (P = 0.05). ACE inhibition with ramipril represents a new macrovascular and microvascular preventive therapy for people with diabetes.